Get rid of code that runs at import in __init__.py.

That was easier than I thought.
Reimplement setUp & tearDown.
Send session at the end of setup.
Reomve example from polymorphic as well.
Real tests!
Change knowledge back. Too much work and it works just fine.
Implement get() to give the value regardless of default.
Moar tests.
Merge branch 'feature/clean_init' into develop
bump version number.
Merge branch 'release/0.3'